A twisting apparatus is known having a support beam on which is mounted a plurality of upright spindles each shaped to carry a respective yarn package from which a filament is pulled and wound up on a takeup spool. The spindles are vertical and each has a whorl engageable with a flat belt that drives the spindle at a high rotation speed that, in conjunction with the speed with which the filament is pulled off the yarn package, determines the extent of twist given the filament. Means is provided to displace each of the spindles away from the belt in order to allow the yarn package carried on the spindle to be replaced or the spinning operation to be stopped when the takeup spool has the desired quantity of filament on it. In addition in case the thread breaks it is necessary to stop the yarn package in order to repair the break.
Typically the spindles are arranged on a pivotal arm such as described in German Gebrauchsmuster No. 6,935,778. The typical arrangement simply has a spring-loaded arm pivoted on the apparatus support and carrying on its free end the spindle, with the spring effective to press the whorl on the spindle against the drive belt. A handle along with locking mechanism is provided so that the arm can be swung around and held in a position with the whorl spaced from the belt. Such arrangements have proven themselves a considerable advantage over systems wherein a magnetic clutch disconnects the package-carrying part of the spindle from the whorl part. In addition such arrangements have proven themselves superior to the systems where the belt is merely pushed away from the spindle by means of a roller or the like, as such devices invariable stretch the belt and eventually require its replacement. Other arrangements are known which merely lock the spindle so that the belt rubs on it without rotating it. Such arrangements are extremely simple, but lead to advanced belt wear and frequently damage the spindle over which the belt is riding.
The principal disadvantage, however, of the pivotal-arm arrangements is that they are relatively bulky and frequently difficult to clean. The spinning process generates a great deal of lint so that the apparatus must be cleaned regularly in order to assure its proper functioning, and cleaning of the interstices of the pivotal arm is relatively difficult. Furthermore the bulkiness of the swinging-arm arrangement reduces the amount of yarn packages that can hold on a given support.